Systems located underground for supplying water to the surface or subsurface of a defined area are well known and take many forms. Such systems are utilized not only in agricultural environments for the irrigation of crops, but also in the sports and recreational fields. Such applications include underground watering systems for football and baseball fields, golf courses and in applications of hard, natural surfaced athletic facilities such as tennis courts and lawn bowling rinks which employ clay or other fast-drying playing surfaces.
Hard lawn tennis courts such as are made with sand, ashes, rubble, brick dust, clay, or the like suffer from the drawback that the upper surface layer dries very quickly and becomes too dusty. As a consequence of becoming dry and dusty, the surface becomes subjected to rapid wear so that frequent repair of the upper layer is necessary, involving considerable expense. To prevent the formation or rising of dust and subsequent surface wear and deterioration, it has, in the past, been the common practice to moisten the surface by sprinkling the surface with water.
The development of underground systems for supplying water to athletic facilities has eliminated the need for manually watering the surfaces of hard surface athletic facilities such as clay tennis courts. However, systems which have been developed heretofore have certain disadvantages in that they tend to be over-complicated and cannot be easily installed into existing athletic facilities without major disruptions to the facility. Additionally, such systems generally incorporate liners which tend to retain water, and thus cause over-Watering during rain.
U.S. Pat. No. 1,665,104 to Martienssen discloses a drainage system for tennis courts which includes a plurality of inclined drain pipes located in a layer of drainage material which is intermediate a lower impermeable layer and an upper plain surface. This system is particularly designed for drainage of the playing field.
U.S. Pat. No. 2,067,356 to Swinhoe discloses a court for games which includes a plurality of parallel pipes which are connected to a water supply pipe. The pipes are located in a compartmented sub-surface layer of the playing field and are covered with a layer of broken stones and an additional layer of ashes. Excess water is drained from the field by means of gaps formed in a brick boundary which surrounds the playing field.
U.S. Pat. No. 4,576,511 to Vidal discloses an apparatus and method for creating and controlling an artificial water table. The system of Vidal includes a reservoir which controls the depth of the artificial water table. Water in the reservoir is allowed to pass through a ballast layer beneath an athletic or agricultural field and pass upwardly through a permeable membrane and into a layer of fine material by capillary action. The depth of water is controlled in the reservoir by means of a water level control float and a drain which is connected to a pump which is operated by an additional float.
U.S. Pat. No. 4,832,526 to Funkhouser discloses an underground watering system for athletic facilities which includes a plurality of trenches having curved bottom surfaces with a waterproof liner located in each of the trenches. An inclined perforated pipe is located in each trench and serves to supply water to the trenches. A course material surrounds the perforated pipes and is covered by a permeable fabric material which in turn is covered by two intermediate stone aggregate layers.
Generally, prior art underground watering systems had to be installed prior to or during the construction of an athletic field surface area. However, the present inventor has developed an underground watering system which may be easily incorporated into existing tennis courts, lawn bowling rinks, and the like, and which may be utilized to both water and drain water from such sports facilities. This system is described in U.S. Pat. No. 5,120,157. A similar system which is designed to compensate for surface topography has been described by the present inventor in U.S. patent application Ser. No. 07/685,399, filed Apr. 16, 1991.
The present invention provides for an underground watering system which is an improvement over previous systems.